Fire-resisting structure



- for rendering 'wooden structures and Patented Dec. 13, 1927.

1,65z,314 UNITED sTATEs PATENT OFFICE.,

FREDERICK O, LUDLOW, F ST. JOSEPH, MICIIGAN, AISSIGNOR TOl THE COMPOUND AND PYBONO DOOR CO., OF ST. JOSEPH, MICHIGAN, A CORPORATION 0F MICHIGAN.

EIEE-EESISTING STRUCTURE.

- nppnction med :une 23,

This invention relates to improved means' ticularly doors and their panels, wainscoting,

ceilings and partitions of buildings lire resistant and temporarily fire proof.

The invention is especially applicable to doors andthe like made with a thick core with surface veneer sheets secured to opposite sides thereof.

The object of the invention is to interpose between the core and each veneer surface sheet materials of such a kind and construction that a greater fire retardation and insulation is obtained kthan with the. ordinary Iuse of asbestos, well known in the art.

The invention consists in devices attaining. the foregoing and otherv objects, which can be easily and chea ly made, which are satisfactory in use an not liable to fail while 1n use.

More particularly'l the invention consistsl in combining the strength, rigidity and density of a metal sheet with the insulating" value of an asbestos sheet, this double protective layer or sheathing being interposed between'a thick combustible core and a thin the finished structure.

F igures3 and 4 are corresponding views of the preferred construction of this invention in which sheets of metal and asbestos are combined with wood in effecting the desired resultsof this invention.

In the structure of Figure 1, a thick wooden core 10 is provided, having -two opposite exterior sheets of veneer 12 and.14, secured to opposite sides thereof. The fireprooin result desired is attained by interposing etween the core and each veneer surface the metallic sheets 16 provided with a multiplicity of generally conical indents 18 driven into' the adjacent surface of the core 1927. serial No. 201,011.

shown, so as to leave` ports or passageways 20 in the tops of the cones through which glue 22,-Y interposed outside the metal sheet 16, may contact with and ladhere to the wood of the core 10. This glue material .22 performs the additional function of securing the adjacent veneer sheet, as 12, -in'position, as clearly shown in the -lefthand half of Figure 2.

In the preferred form of construction shown in Figures 3 and 4, a central core 24` and veneer'sheets 28 and 28 are substituted for the wooden parts shown in Figure 1.A A

4metal sheet 30 of the same general form is substituted for the metal sheet 16 of Figure 2. To' the back or outside of each metal sheet 3() is securedl by glue 32 anasbestos sheet 34 pressed into the conical indentations'36 of metal -sheet 30 corresponding to the conica-l members 18 of Figure 2. Glue 38 is applied to the rear or outside surface of the asbestos sheet 34 for the purpose ofsecuring the adjacent veneer sheet, as 28, in the lefthand side of Figure 4.

The vindented members 18 and 36 have been referred to as conical'. As shown in the drawings in which these indentationsA are in fact rectangular, there is no limitation .in this phrase to any particular cross-sectional form as circular or rectangular.

The conical indents 18 and 36, referred to,

perform the valued function of affording resistance to the shearing strain in the glue jointsbetween the various sheets of material. They also form a very important feature of providing in their broken, open tops means for the escape of gases set :treel from the body of the core 10 or 24, as the case may be, under fire conditions, it being well known that if no vent or escape is provided for a structure of this kind, the pressure of gases created in the core under heat against the door or the like using the construction of this invention tends to loosen or blow olf the protective layer or sheath which is attached to the core. The indenting of the double protective sheathing of Figures 3 and 4 is further useful in obtaining the glue bond for the thinv vveneer laidover the structure so as to provide a finished surface for paint or,` stain. The strength vof this glue bond is greatly enhanced by portions of the glue entering the indents and adhering directly to the core at frequent intervals as shown in the drawings.

Actual tests have demonstrated that the use of the metal sheets 16 and 34 greatly increases the fire resistance of structures of this kind as com ared with prior structures in which only as estos is used. Actual tests of structures of this kind under fire conditions have shown that the veneer sheet-on the fire side may be burned away and the. core gartially or completely charred and yet the oor or other Wall constructed in accord` ance with this invention stands as a barrier to the progress of re because of the metal sheet adjacent to the fire having suiiicient strength to stand up during the lire and retain its position glued to the charred core of the door or the like built in accordance with this invention.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In a fire resisting structure, a combustible core, a metallic sheet adjacent to and indented into the core, the tops of the indents being perforated, adhesive material outside the metal sheet extending through the indents and a sheet of diierent material secured in place by said adhesive material.

2. In a iire resisting structure, a combus? `outside the metal sheet extending through the indents and a sheet of veneer secured in place by said adhesive material.

3. In a fire resisting structure,. a combus tible core, a metallic sheet 'adjacent to and indented into the core, the tops of the indents heing perforated, adhesive material outside the metal sheet extending through` the indents and a sheet of asbestos secured in place by said adhesive material.

4. In a fire resisting structure, a combus tible core, a metallic sheet adjacent to and indented into the core, the tops of the indents being perforated, adhesive material outside the metal sheet extending throu h the indents, a sheetfof asbestos secured 1n place by said adhesive material anda sheet of veneer secured to the outside of the asbestos.

In witness whereof,` I have hereunto subscribed my name.

FREDERICK O. LUDLOW. 

